I just read through 1Password release notes [0], "Addressed a bug in the new popup where items were checked for vulnerable passwords even if you hadn't opted in to the Have I Been Pwned service." which also links to a KB article that talks about the security risks of HIBP [1]

I would be very concerned if my credentials are being shared in _any_ form with 3rd parties without my explicit permissions.

I hope this firefox feature is disabled by default.

[0] https://app-updates.agilebits.com/product_history/B5X [1] https://support.1password.com/kb/201907/